Yunkai Desktop Bridge

A local-first Windows MCP bridge for guarded desktop perception and interaction.

This repository is a sanitized public-source export of the DesktopBridge used in the Yunkai project. It keeps the control boundaries that matter: semantic/read-only inspection first, bounded input actions, local runtime policy, deterministic verification, metadata-only action audit, and no arbitrary shell.

Highlights

• Windows virtual-desktop and active-window screenshots

• Microsoft UI Automation (UIA) semantic inspection

• Win32 control fallback

• guarded mouse and keyboard input

• verified UIA click/text actions with expected-post predicates

• bounded game-input mode behind a separate local permission tier

• localhost-only optional vision fallback

• local DPAPI-backed secret aliases; secret values are never accepted as remote MCP arguments

• capability manifest, runtime permission state, routing hints, device snapshot, and action trace surfaces

Related MCP server: win-nav

Deliberate non-capabilities

The public MCP surface does not expose arbitrary shell/PowerShell/cmd execution, file deletion, software uninstall, shutdown/reboot, registry modification, unrestricted process kill, or remote secret upload.

Public export boundary

This repository does not contain private tunnel IDs, runtime credentials, owner-specific configuration, caches, backups, local verification evidence, or tunnel-client binaries. Machine-specific DevSpace routing code is intentionally excluded from this public bridge.

The shared contract modules required by the bridge are included under yunkai_shared/.

Requirements

• Windows 10/11

• Python 3.10+

• Microsoft UI Automation (built into Windows)

• Python dependencies in requirements.txt

Quick start

git clone https://github.com/YunkaiLim/yunkai-desktop-bridge.git
cd yunkai-desktop-bridge
py -m venv .venv
.\.venv\Scripts\Activate.ps1
pip install -r requirements.txt
cd DesktopBridge
python server_stdio.py

For the local HTTP entry point:

cd DesktopBridge
python server.py

Optional localhost vision can be configured by copying DesktopBridge/desktopbridge_vision.example.json to desktopbridge_vision.json and selecting a compatible local vision model.

Tests

From DesktopBridge/:

python -m unittest

During public-release preparation on 2026-09-30, the selected public test set passed 104 tests, including stdio MCP discovery and screenshot/content checks.

A passing unit suite is not proof of live acceptance on every Windows build or MCP host. Perform target-machine acceptance separately.

Security model

Read SECURITY.md before enabling side-effecting tools. Keep runtime permissions local, preserve foreground-window and semantic-target guards, and do not remove verification simply to reduce latency.

License

Apache-2.0. See LICENSE and NOTICE.

Third-party components are not relicensed by this repository; see THIRD_PARTY_NOTICES.md.

This project is independent source code and is not an official OpenAI product.